Passenger vehicles often include electric batteries for operating features of vehicle electrical and drivetrain systems. For example, vehicles commonly include a 12V lead-acid automotive battery configured to supply electric energy to vehicle starter systems (e.g., a starter motor), lighting systems, and/or ignition systems. In electric, fuel cell (“FC”), and/or hybrid vehicles, a low voltage vehicle battery may be used to supply electric energy to a certain subset of vehicle features not powered by a high voltage (“HV”) battery system used primarily to power electric drivetrain components (e.g., electric drive motors and the like).
Over sustained periods of vehicle non-use, the state-of-charge (“SOC”) of a vehicle battery may fall to undesirably low levels. For example, in certain circumstances, some vehicle electrical systems (e.g., clocks, vehicle alarms, and the like) may continue to draw electrical energy from the vehicle battery even when the vehicle is not operating. In further circumstances, a vehicle operator may inadvertently leave on lighting systems and/or other vehicle systems that draw energy from the vehicle battery when the vehicle is not operating. Over sustained periods, this may cause the vehicle battery to deplete.
FC systems included in FC electric vehicles may experience progressive damage under sustained periods of non-use (i.e., “off-time”). To mitigate this damage, hydrogen may be periodically introduced into the FC system to maintain a hydrogen-rich environment in the system. Periodically introducing hydrogen into the FC system, however, may also undesirably contribute to the depletion of the vehicle's battery (e.g., the low voltage battery), due to the potential use of electrical power to operate valves, sensors and/or controllers.